1. Field of the Invention
The invention relates to a digital platform scale of the general type of home weighing scale that is connected to an electrical digital readout and, more particularly, to a differential transformer mechanism that is the sole integral link of the balance system directly in line with the bias spring for maximum sensitivity and minimum frictional effect on the system.
2. Description of the Prior Art
The common household bathroom scale having a base and a weight supporting cover with an internal lever system biased by a coil spring and the lever system actuating a readout, usually in the form of a rotating calibrated dial, is well known. Improvements have been proposed in the general combination that employ digital readouts as in U.S. Pat. No. 4,041,289 and in scales that are electronically operated by coils or differential transformers with the readout being directly on the scale or at a remote point. Typical of the coil is shown in U.S. Pat. No. 3,469,645 and differential transformer is shown in U.S. Pat. No. 3,887,797. All such scales either locate the sensor at a point removed from the maximum lever travel or employ a sensor and/or readout that imposes some frictional resistance on the movement of the lever system e.g. a dial mechanism or rack and pinion operating off the lever system. Any improvements on such scales are generally directed to increasing sensitivity and minimizing the friction inherent in the system to provide for more accurate readings and it is to this end that the present invention is directed.